Why the Pioneer probes are decelerating

[Smivs]

In 1998 it was revealed that both Pioneers 10 and 11 were decelerating.This phenomenon was not expected and there was no obvious explanation for this, although it had been known about for 15 years. Theoretical explanations ranged from the influence of dark matter to an effect caused by the expansion of the universe.
Eventually, the real reason was determined and although less esoteric than some of the theories, it is still fascinating.

[DaddyHoggy]

Fantastic story.

I love physics me!

[Wolfwood]

Ah, excellent article! It was a pleasure to read.

And nice to see that physics sometimes produces answers that don't require dark matter, mirror universes or other mysterious forces to work.

[Rese249er]

...nice to see that physics sometimes produces answers that don't require dark matter, mirror universes or other mysterious forces to work.

Ah, but esoteric and mysterious-sounding explanations generate hype, which means the particular scientist with that explanation is better off... I think.

Something like that. I dunno. I'm a pilot, not a physicist.

[Selezen]

Wonderful! Heat and light cause deceleration. Interesting to read along with the main point of the article that the photons emitted from high beam headlights can decelerate your car.

What would the deceleration factor of a Military laser be? Or a large plasma accelerator?? Should this be modelled into Oolite's physics?? Inquiring minds want to know!!

[Eric Walch]

The magnitude of the force was still tiny by Earth standards—about the same as the backward push your car experiences in reaction to the photons spit out by its high-beam headlights.

So, this means I should keep my headlight switched off in future to be able to drive faster.

Although it is not my experience: my car drives really slower, when not using headlights in a dark forest road.

[cim]

So, this means I should keep my headlight switched off in future to be able to drive faster.

Worse, your brakes will actually speed you up by ejecting reaction mass out of the back of your car.

[Smivs]

Smivs fits bigger side repeaters to his car to improve yaw control

[Selezen]

Headlights are always much brighter than tail lights. Theory: drive backwards to increase fuel efficiency. Or fit halogen foglights to the back of your car for additional thrust.

[CommRLock78]

The magnitude of the force was still tiny by Earth standards—about the same as the backward push your car experiences in reaction to the photons spit out by its high-beam headlights.

So, this means I should keep my headlight switched off in future to be able to drive faster.

Although it is not my experience: my car drives really slower, when not using headlights in a dark forest road.

. Mundane explanation perhaps, but interesting that these probes are likely to hold the distinction of being the most precisely navigated probes yet sent into space for some time to come (I would have thought the Voyagers were more precisely navigated, being later probes). Excellent article; thanks for sharing Smivs .

[Cody]

About forty years since the Pioneer probes launched... and exactly forty years today since Apollo XVII launched. <sighs wistfully>

[CommRLock78]

<sighs wistfully>

It is sad - However, I'm fully confident this curious, monkey species we belong to will go back, eventually

[DaddyHoggy]

<sighs wistfully>

It is sad - However, I'm fully confident this curious, monkey species we belong to will go back, eventually

I was thinking of starting a KickStarter...

http://www.newscientist.com/article/dn2 ... trips.html